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The global surge in multi-drug resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has led to a growing need for new antibacterial compounds. Despite being promising, the potential of fish-derived antimicrobial peptides (AMPs) in combating ESBL-producing E. coli is largely unexplored. In this study, native African catfish antimicrobial peptides (NACAPs) were extracted from the skin mucus of farmed African catfish, Clarias gariepinus, using a combination of 10% acetic acid solvent hydrolysis, 5 kDa ultrafiltration, and C18 hydrophobic interaction chromatography. Peptides were then sequenced using Orbitrap Fusion Lumos Tribrid Mass Spectrometry. The identified peptides were screened for potential antibacterial activity using Random Forest and AdaBoost machine learning algorithms. The most promising peptide was chemically synthesized and evaluated in vitro for safety on rabbit red blood cells and activity against ESBL-producing E. coli (ATCC 35218) utilizing spot-on-lawn and broth dilution methods. Eight peptides ranging from 13 to 22 amino acids with molecular weights between 968.42 and 2434.11 Da were identified. Peptide NACAP-II was non-hemolytic to rabbit erythrocytes (p > 0.05) with a zone of inhibition (ZOI) of 22.7 ± 0.9 mm and a minimum inhibitory concentration (MIC) of 91.3 ± 1.2 μg/mL. The peptide is thus a candidate antibacterial compound with enormous potential applications in the pharmaceutical industry. However, further studies are still required to establish an upscale production strategy and optimize its activity and safety in vivo.

In light of Vietnam's significant role as a top ten seafood exporter, particularly in shrimp and catfish, the COVID-19 pandemic has disrupted the nation's crucial seafood production and exports since early 2020. Our investigation, which is based on farmer surveys and enterprise interviews, has revealed a significant increase in production costs, especially in intensive shrimp farming, which has had a greater impact on compared to semi-intensive farming. Approximately 51.6% of farmers reported a strong effect on feed expenses, with 39.6% categorizing it as a very strong effect. This represents a significant impact on input costs, primarily due to challenges in sourcing materials, particularly feed, which constitutes the highest proportion of production costs. Challenges in goods exchange along the supply chain were strongly reported by 75% of enterprises, with 25% describing them as very strong, thus affecting production costs and inventory. Labor costs have also increased due to COVID-19, with 25% reporting a strong influence and 75% indicating a stable impact. The pandemic has affected commercial pangasius prices, with 29.7% of respondents noting a decrease and 41.8% confirming increased raw material costs, especially for fish feed. Feed costs account for 85.6%, while seed costs comprise 5.1% of total expenditure. Supply chain disruptions have led to enterprises having to suspend operations or reduce operating capacity to 30–40% due to a shortage of workers. The paper suggested practical management and technical solutions, emphasizing the need for supportive policies and a government-led mechanism to assist workers. This study offers valuable insights into the industry's resilience and adaptive mechanisms to face post-pandemic challenges. [ABSTRACT FROM AUTHOR]

With rapid urbanisation coupled with the influx of more people to Ado-Ekiti, it is pertinent to assess the effect of human activities on living organisms in Ureje River, the main water body that cuts across Ado-Ekiti. This study examined the effects of environmental pollution on the Ureje River in Ado Ekiti, Nigeria with focus on water quality, heavy metal contamination, and the health of female African catfish. Samples of water were fetched from various fishing spots along the river, and an earthen pond, which served as a control. Blood samples were collected from fish samples farmed from different fishing points, and thereafter slaughtered and organ characteristics and histology assessed. Fish from Emirin and Erinfun showed lower (p<0.05) weights, indicating impaired growth. Fish had significantly (p<0.05) elevated glucose at Ajebamidele, high total protein at Aduloju, Erinfun and Ajebamidele, and varied cholesterol levels, reflecting metabolic stress. Fish from polluted points had notably higher liver enzymes and alkaline phosphatase coupled with highest oxidative stress, indicating liver damage and stress. Fish from heavily polluted areas had necrosis in gills, liver steatosis, and kidney infiltration. Pollution from industrial, agricultural, and domestic sources significantly degrades the Ureje River ecosystem with negatives impacts on water quality and aquatic organism health [ABSTRACT FROM AUTHOR]

The genetic variabilities in internal transcribed spacers ITS1 and ITS2 of rDNA are explored to a limited extent in vertebrates including fish species. This study explores unique molecular signature in these spacers from multiple catfish species from the order siluriformes. Supporting the concerted evolution, both ITS1 and ITS2 were found prevalent with microsatellite and random repeats, with diverse distribution in each species in terms of nucleotide composition, their position and length, giving a species-specific impression in repeats. Their secondary structures too have shown distinct structural homology with variations in helix lengths, loops, and non-canonical base pairs, where ITS2 4-helix carries additional nine conserved motifs while that of ITS1 was found highly branched with multiple sub-branching unique to each species and a long tail helix common in all. This combination of secondary structures and repeats have formed unique molecular signatures distinguishing each catfish species. Since the evolutionary and maturation biology of rDNA is similar in vertebrates, these molecular signatures in internal spacers could effectively contribute to the molecular characterization across the diverse group of catfish species. [ABSTRACT FROM AUTHOR]

A newly isolated rhabdovirus-like agent, named SHRV-In, obtained from snakehead fish in India was further characterized in this study. The virus demonstrated growth in various cell lines including those derived from snakehead and seabass species. It exhibited sensitivity to acidic conditions (pH 3.0) and exposure to 56 °C. Five structural proteins of 20 to 68 kDa were found in the purified virus. Experimental infection trials conducted on catfish (Pangasius pangasius) resulted in mortality 72 h post-infection, whereas no mortality was observed in rohu (Labeo rohita) and common carp (Cyprinus carpio) fingerlings. Molecular characterization of the virus involved sequencing of the N, P, M, and G gene fragments after PCR amplification using specific primers. Sequence analysis of all four viral genes showed high similarity with the previously isolated snakehead rhabdovirus (SHRV) from Thailand. Phylogenetic analysis and gene sequence alignment placed the SHRV-In isolate within the Novirhabdovirus group, which includes viruses like VHSV (viral hemorrhagic septicemia virus), IHNV (infectious hematopoietic necrosis virus), and SHRV. However, our repeated trials failed to amplify the NV gene in this isolate SHRV-In. [ABSTRACT FROM AUTHOR]

Branchiura are a crustacean parasite widely known around the world as fish lice. In South America, they have been most studied in Brazil as with high levels of infestation, the parasites can be harmful to the health of fish and cause economic losses in fish farms. The objective of the present study is to provide, for the first time, significant information about the parasitic indices, infestation sites, and morphology of Dolops carvalhoi, and to report the appearance of a new host in the Amazon region of Peru. A total of 24 specimens of Colossoma macropomum, Piaractus brachypomus, and Calophysus macropterus from fish farms were individually analyzed to identify the presence of the ectoparasites. The Branchiura collected from the body surfaces of the fish were separated according to sex, the parasitic indices were calculated, and the parasites were clarified in 90% lactic acid for taxonomic identification. They were also preserved in 2.5% glutaraldehyde, and dehydration and critical point procedures were applied by scanning electron microscopy to visualize the detailed structures. The taxa identified was D. carvalhoi, which had a prevalence of 64.7%, a mean intensity of 1.6, and a mean abundance of 1 parasite/fish in C. macropterus; a prevalence of 100%, a mean intensity, and mean abundance of 2.8 parasites/fish in P. brachypomus; and a prevalence of 100%, but a mean intensity and mean abundance of 15 parasites/fish in C. macropomum. The pectoral and dorsal fins and the urogenital opening had the highest occurrence of D. carvalhoi in the host. Dolops carvalhoi has sexual dimorphism, and we reported for the first time the infestation of this parasite in leather fish C. macropterus. [ABSTRACT FROM AUTHOR]

As an important contributor to Louisiana’s economy, the commercial freshwater fisheries have been the subject of growing attention in recent years by resource managers as the industry appears to be on the brink of collapse. Fewer participants are entering the field, fish buyers and processors are closing, and market prices remain stagnant. To better understand this industry, we conducted a study to characterize the commercial freshwater fisheries in Louisiana including the fishermen, the fishing operations, the effort across the state, local knowledge on management issue and barriers and opportunities for the future of the industry. We completed structured interviews at fish houses across Louisiana. The average full-time fisherman was 56 years old with about 34 years of commercial fishing experience, and catfish (Ictaluridae spp.) and buffalo (Ictobius spp.) appear to be the most sought-after finfish; however, this slightly differs by region. Overall, this study provides in-depth insight into the trends, problems, and successes of Louisiana’s freshwater commercial fisheries. This information will allow managers and other groups like cooperative extension to identify and design opportunities for the industry and utilize their information in management across the state. [ABSTRACT FROM AUTHOR]

This study aimed to explore the effects of heat stress and black sand acute exposure on the erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices. Catfish were subjected to black sand nanoparticles (6.4 g of nanoparticles black sand per kg of diet), thermal stress (32 °C), and a combined treatment involving both stressors over a period of 15 days. Catfish exposed to black sand nanoparticles and heat stress singly and/or in combination showed significantly lower red blood cells (RBCs) count, hemoglobin (Hb), platelets, white blood cells (WBCs) count, large lymphocytes, small lymphocytes, and monocytes. Antioxidant indices decreased in black sand NPs and heat stress combination compared to other groups. Notably, the combination of black sand nanoparticles and heat stress led to a substantial increase in the percentages of both RBCs alterations and nuclear abnormalities. Histological examinations of the liver revealed various features, including intracellular bleeding, cytoplasmic vacuolation, tissue deterioration, hepatocyte pyknotic nuclei, nuclear displacement, shrinkage, and accumulation of melanomacrophage cells. In conclusion, the study underscores that the effects of black sand nanoparticles on erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices, become more pronounced under elevated temperatures indicating the potential for synergistic effects between pollution and climate change. This holistic approach is crucial for developing more accurate forecasts of the complex interactions between environmental stressors and their implications for aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Medicinal plants and plant extracts have been employed by rural fish farmers in fish management. This present study was designed to investigate the ameliorative effect of a medicinal plant, bitter leaf (Vernonia amagdalina) extract on African catfish (Clarias gariepinus) fingerlings contaminated with diclofenac using biometric and oxidative stress indices. The fingerlings were exposed to different concentrations of both bitter leaf extract (BLE) (2 and 6% body weight) and diclofenac (DCF) (0.3 and 0.4 mg/L) after a series of range-finding tests. The length and weight of the experimental fishes were taken weekly from different concentrations and were used to calculate the growth parameter. There were no significant differences (p<0.05) among the treatments in mean weight gain, specific growth rate, feed conversion ratio and condition factor when compared to their various control groups. Liver tissues of the experimental fishes were collected on the 14th and 28th day, from different concentrations and were assay for oxidative stress. The antioxidants: CAT (30.22 ± 0.148 to 66.50 ± 0.707) and MDA (22.61 ± 0.233 to 66.50 ± 3.536) increased significantly when compared to the control. The results indicated that the given concentration of diclofenac and V. amygdalina cause significant alteration in the oxidative stress of C. gariepinus and may have no adverse effect on the growth of C. gariepinus. However, this study did not show the detoxifying potential of V. amygdalina against the adverse effect of diclofenac in C. gariepinus. [ABSTRACT FROM AUTHOR]

Ivermectin is one of human and veterinary medicine's most widely used antiparasitic drugs. Reports of low tolerance margins have accompanied its use in aquaculture. This study assessed the behavioural changes in African catfish - Clarias gariepinus exposed to ivermectin. Further, acute toxicity, no effect concentration, least effect concentration, and safe level of ivermectin were determined. Mortality was recorded for all the ivermectin concentrations used; this ranged from 13% to 100% for concentrations between 1.6 µgl-1 and 24.3 µgl-1. There were changes in behavioural profiles of the fish especially at higher concentrations of the drug. The LC50 values at 24, 48, 72 and 96 hours were 46.58 (22.45 - 450.81), 38.71 (17.69 - 648.27), 12.38 (8.19 - 24.50) and 6.53 (2.86 - 17.43) µgl-1 respectively. The 96-hour estimated safe level of ivermectin based on the NAS/NAE method is 6.53 x 10-1 - 6.53 x 10-5. Ivermectin was able to cause 100% mortality in catfish at 24.3 µgl-1. The low margin of safety and low toxic unit of 0.07 of the drugs make it unsuitable for use in aquaculture for the control of parasites. [ABSTRACT FROM AUTHOR]

The inappropriate disposal of wastes causes an imbalance in natural aquatic ecosystems, affecting the marine environments, human health, and productive activities. This present study was designed to investigate the ameliorative effect of a medicinal plant, bitter leaf extract (BLE) on African catfish (Clarias gariepinus) fingerlings contaminated with diclofenac (DFC) using amino acid profile indices. The fingerlings were exposed to different concentrations of both BLE (6% body weight) and DCF (0.4mg/L) after a series of rangefinding tests. Liver tissues of the experimental fishes were collected on the 14th and 28th day and were analyzed for the assessment of amino acid profile. The result obtained on the amino acid profile of C. gariepinus showed a significant increase (p<0.05) in the treatments with BLE (1.06 ± 0.04 to 15.22 ± 0.01) and DCF (0.48 ± 0.04 to 14.79 ± 0.04) when compared to their control group. Glycine, alanine, serine, glutamate, arginine, tyrosine, leucine and histidine showed a significant increase (p<0.05) while cystine and methionine showed a significant decrease (p<0.05) when compared to their control groups (0.29 ± 0.00 to 13.77 ± 0.04). Threonine, valine, isoleucine, tryptophan, phenylalanine, aspartate, proline and lysine varied when compared to their control groups. The results indicate that the given concentration of DCF and V. amygdalina may have no adverse effect on the amino acid profile of C. gariepinus. However, this study has shown the ameliorative potential of V. amygdalin against the effect of DCF in C. gariepinus. [ABSTRACT FROM AUTHOR]

Introduction: Geometric aquaculture growth has resulted in exponentially increasing use of agrochemicals as either parasiticides or herbicides in the aquaculture environment. This study determines some of the toxicological (haematological and biochemical) effects of glyphosate-based herbicides on non-target aquatic animals using Clarias gariepinus as the animal model. Method: Seventy-five apparently healthy adult C. gariepinus (300 g) were sourced from a local farmer and acclimatised for 2 weeks; of these, sixty subjects were divided into four treatment groups (fifteen fish per group and five replicates per unit) by simple randomisation and labelled as T0 (control), T1 (first treatment), T2 (second treatment), and T3 (third treatment). The treatments were replicated thrice. Four concentrations of Force up® [0 mL, 0.15 mL (0.003 mL/L or 5.1 mg/L), 0.225 mL (0.0045 mL/L or 7.65 mg/L), and 0.3 mL (0.006 mL/L or 10.2 mg/L) were added to a 50-L tank of water for T0, T1, T2, and T3, respectively. Approximately 5 mL of blood was collected from the fish in each treatment group 96 h post-exposure for measurement of the blood parameters and biochemical indices using standard analytical methods as well as calculation of the mean values. Result: The mean values of the packed cell volume, haemoglobin concentration, red blood cell count, and white blood cell count compared to the control group showed an initial increase at T1 but decreased as the glyphosate concentrations increased at T2 (0.0045 mL/L) and T3 (0.006 mL/L). The platelet mean values decreased at T1, increased at T2, and decreased at T3, while the mean values of the corpuscular volume, corpuscular haemoglobin, and corpuscular haemoglobin concentration increased with glyphosate concentration, with the mean corpuscular haemoglobin concentration decreasing at T2. Only the platelet value was statistically significant at a p -value of <0.05 using ANOVA and post hoc Tukey test. The biochemical indices showed decreases in the mean values of aspartate transaminase, blood urea nitrogen, creatinine, and triglycerides at T1, increases at T2, and decreases at T3, while the total protein (g/dL), cholesterol, alanine transaminase, and alkaline phosphatase values showed increases at T1 and decreases at T2 and T3. All these values were not statistically significant based on ANOVA and had p -values >0.05. Discussion: Based on the results of this study, it is deduced that glyphosate-based herbicide (Force up®) has genotoxic, hepatotoxic, and nephrotoxic effects on C. gariepinus even at sublethal doses, with more adverse effects at increasing concentrations. [ABSTRACT FROM AUTHOR]

The Zambezi grunter, Parauchenoglanis ngamensis , is currently distributed across four (sub)basins in southern and south-central Africa, namely the Okavango, upper Zambezi, Kwanza, and Kasai. The present study used a combination of molecular (barcoding), colour pattern, and other morphological data to explore the possible existence of hidden species diversity within this species. Based on the available samples, analyses of molecular data uncovered seven well-supported (.96–1.00 Bayesian posterior probabilities) candidate species, with 1.6%−8.5% genetic divergence between them. These, in addition to two more candidate species without genetic data, exhibited a combination of consistent colour pattern and other morphological differences that supported their distinction. The present study redescribes P. ngamensis , which is confined to the Okavango and upper Zambezi (sub)basins, and describes eight new species: two from the Kwanza Basin and six from the Kasai sub-basin. The fact that some of the species occur allopatrically, whereas others are sympatric and even syntopic indicates the complex palaeogeographical history of these basins. In addition, the high species diversity discovered in the Kasai sub-basin seems to be related to its highly peculiar hydrography. Accurate delimitation of species boundaries and mapping of their distribution is crucial for conservation assessments and guiding their protection. [ABSTRACT FROM AUTHOR]

The African catfish (Clarias gariepinus) is known for its resilience in extreme conditions; however, it is not widely accepted by most Egyptian consumers. This study aimed to determine the biochemical and sensory quality of fish spread made from the catfish meat, with varying levels of potato substitution. Five treatments were designed: a control (without potatoes) and four treatments with 5, 10, 15, and 20% potatoes. The results showed that the control spread contained 63.24% moisture, 16.05% crude protein, 16.60% fat, 2.25% ash, and 1.68% carbohydrates. Additionally, the quality indices recorded were pH 6.51, TVN 13.02mg/ 100g, TBA 0.23mg MDA/kg sample, and TPC 43x10² cfu/g. These values varied with each treatment, showing significant changes in both protein and carbohydrate content. Regarding sensory quality, the fish spread with 10% potatoes received a high score for color, while the treatment with 15% potatoes achieved high scores in color, spreadability, aftertaste, and overall acceptability. In conclusion, spreads made from the catfish were well accepted by panelists, and the inclusion of potatoes up to 15% improved both the biochemical and sensory quality. This study recommends that underutilized catfish be considered a good source for creating suitable fish spreads for all ages. [ABSTRACT FROM AUTHOR]

Ictalurid herpesvirus 1 (IcHV1) is the most significant viral agent in U.S. catfish aquaculture. Little is known regarding the genetic stability and antigenic variability of IcHV1. Herein, the genetic and antigenic diversity of IcHV1 field isolates was assessed by restriction fragment length polymorphism (RFLP) analysis and serum neutralization assays. RFLP analysis identified two distinct genotypes (IcHV1A and IcHV1B), both discrete from blue catfish alloherpesvirus (BCAHV). Neutralization assays with anti‐IcHV1 monoclonal antibody Mab‐95 indicate shared antigenic determinants for IcHV1A and IcHV1B that are absent from BCAHV, which Mab‐95 did not neutralize. Virulence assessments with representative isolates demonstrate significant differences between isolates within RFLP groups and pooled RFLP group data suggest IcHV1B (pooled survival [mean ± SE]: 58.3% ± 2.6) may be more virulent than IcHV1A (survival: 68.6% ± 2.4). Rechallenges with representative IcHV1A and IcHV1B isolates indicate a cross‐protective effect, with fish surviving initial exposure to IcHV1A or IcHV1B showing robust protection when subsequently re‐exposed to IcHV1A or IcHV1B. This work demonstrated significant differences in virulence between case isolates, identifying two discrete IcHV1 lineages, distinct from BCAHV, with similar virulence in channel and channel × blue catfish hybrids and a cross‐protective effect in catfish surviving exposure to either lineage. [ABSTRACT FROM AUTHOR]

Proliferative gill disease (PGD), caused by the myxozoan Henneguya ictaluri, has been the most notorious parasitic gill disease in the US catfish aquaculture industry. In 2019, an unusual gill disease caused by massive burdens of another myxozoan, Henneguya exilis, was described in channel (Ictalurus punctatus) × blue (Ictalurus furcatus) hybrid catfish. Targeted metagenomic sequencing and in situ hybridization (ISH) were used to differentiate these conditions by comparing myxozoan communities involved in lesion development and disease pathogenesis between massive H. exilis infections and PGD cases. Thirty ethanol-fixed gill holobranchs from 7 cases of massive H. exilis infection in hybrid catfish were subjected to targeted amplicon sequencing of the 18S rRNA gene and compared to a targeted metagenomic data set previously generated from clinical PGD case submissions. Furthermore, serial sections of 14 formalin-fixed gill holobranchs (2 per case) were analyzed by RNAscope duplex chromogenic ISH assays targeting 8 different myxozoan species. Targeted metagenomic and ISH data were concordant, indicating myxozoan community compositions significantly differ between PGD and massive branchial henneguyosis. Although PGD cases often consist of mixed species infections, massive branchial henneguyosis consisted of nearly pure H. exilis infections. Still, H. ictaluri was identified by ISH in association with infrequent PGD lesions, suggesting coinfections occur, and some cases of massive branchial henneguyosis may contain concurrent PGD lesions contributing to morbidity. These findings establish a case definition for a putative emerging, myxozoan-induced gill disease of farm-raised catfish with a proposed condition name of massive branchial henneguyosis of catfish (MBHC). [ABSTRACT FROM AUTHOR]

To prevent anemia in pregnant women, it is necessary to develop food products that are sources of nutrients, for example from mung beans. Mung beans can be processed into snacks such as tortilla wrap mung beans. This study aims to determine the recipe, level of preference, and nutritional content of tortilla wrap mung beans with catfish filling. This type of research uses RD (Research and Development) with a 4D design (Define, Design, Development and Disseminate). The preference test was carried out by 100 panelists of pregnant women and the proximate test on innovative products. Data analysis used descriptive statistics. The Tortilla Wrap Mung Beans recipe uses 30% substitution of mung bean flour from the total wheat flour. Overall, the level of preference for tortilla wrap mung beans has an average of 3.46 or preferred. The nutritional content of tortillawrap mung beans per serving (100 g) consists of energy 275.8 kcal, protein 11.49 g, fat 9.01 g, carbohydrates 42.26 g. Tortilla wrap mung beans is categorized as an iron source snack because the iron content is 15.75 mg per 100 g of product. Therefore, tortilla wrap mung beans with catfish filling can be recommended as an alternative snack source of iron for pregnant women.

Portioning large fish fillets for packaging is usually performed manually by skilled workers. Automating this process and obtaining packaged products with attractive shapes and affordable weights will be beneficial for promoting purchase decisions. Towards developing an automated fish fillet portioning system, this study investigated a computer vision approach for determining the fillet volume. A belt conveyor would transport a fish fillet to the image capture booth, where its cross-section areas would be calculated for volume determination. The developed system could be operated with a conveyor speed ranging from 7.5 to 30.6 mm/s. The system performance was evaluated at a conveyor speed of 7.5 mm/s using small catfish fillets from 142.2 to 225.4 cm3. A mean percent error of 9.2% was observed, and the smallest percent error of 3.8% was obtained with a 225.4 cm3 fillet. With minor measurement errors obtained for larger fillets, the proposed computer vision system showed great potential for developing a cost-effective automated system for customized fish fillet partitioning to accelerate purchase decisions and also for quality control and classification of the fish fillets. [ABSTRACT FROM AUTHOR]

Abstract Endocrine cells in the fundic stomach of Clarias gariepinus were characterized in this work using transmission electron microscopy, immunohistochemistry, and histochemistry. Performic acid mixed with alcian blue pH2.5 and silver stain were among the histochemical stains used for endocrine cells. Endocrine cells can be found in the epithelium, lamina propria, submucosa, muscular layer, serosa, and the area between the stomach glands. Endocrine cells with one or more nuclei were found. Endocrine cells were studied using CD3, CD21, and CD68 in an immunohistochemistry analysis. The expression of the lymphocyte marker CD3 by endocrine cells is remarkable. In addition, they had a strong immunological response to CD21 and CD68, which are characteristics of phagocytic cells. Granules of varied sizes and electron densities are packed densely into the cytoplasm of the cells, as seen by transmission electron microscopy. We propose that endocrine cells play a crucial role in immune defense. The role of endocrine cells in the gut’s immune system is an area that needs further investigation.

Abstract In Egypt, while many studies have focused on the radiometry and mineralogy of black sands, research on their effects on nearby aquatic organisms is rare. This study aimed to assess the combined effects of heat stress (HS) and black sand nanoparticles (BS-NPs) on renal function, antioxidant responses (TAC, SOD, CAT), neuro-stress indicators (AchE, cortisol), and to conduct histopathological investigations in the kidney and spleen tissues of African catfish Clarias gariepinus over a 15-day period to exposure to control, HS (32 °C), BS (6.4 g/kg diet) and HS + BS groups. The outcomes revealed that thermal stress alone showed no significant difference from the control. However, creatinine and uric acid levels were significantly higher in the BS-NPs and HS + BS-NPs groups (p

ABSTRACT Edwardsiella ictaluri and Flavobacterium covae are two bacteria species that cause diseases in farm‐raised channel catfish (Ictalurus punctatus) that cause heavy economic damage to the aquaculture industry, particularly to the channel catfish farming. In search for environmentally benign antibacterial compounds active against E. ictaluri and F. covae, we investigated the constituents isolated from Brazilian red, brown and green propolis. We have also synthetically modified active constituents to see if lipophilicity plays a role in enhancing antibacterial activities. Vestitol, neovestitol and methylvestitol were found to be the active constituents with minimum inhibitory concentration (MIC) relative to drug control florfenicol (RDCF) values (MIC−RDCF) of 7.6, 7.6 and 7.9 mg/L, respectively, against F. covae. The activity against E. ictaluri was not significant. [ABSTRACT FROM AUTHOR]

The impact of dietary fenugreek (FN) supplementation on growth performance, physio‐metabolic enzyme response, and antioxidant enzyme activities in hybrid African catfish (Clarias gariepinus ♀ × Heterobranchus bidorsalis ♂) was investigated in this study. Five isonitrogenous diets (38% crude protein) were developed and fed to the fish for 60 days. The FN was incorporated into the diets at 0%, 0.5%, 1.0%, 1.5%, and 2%. Two hundred twenty‐five fingerlings of hybrid African catfish (average weight 4.01 g ± 0.02) were used for the study and randomly distributed to five dietary groups in triplicate. FN supplementation improved growth responses and survival rates; the dietary groups considerably (p < 0.05) outperformed the control group. FN‐based diets considerably increased the carcass protein content (p = 0.020) and improved protein retention (p = 0.015). FN supplementation markedly (p < 0.001) and dose‐dependently reduced the carcass's lipid content and substantially (p < 0.001) increased the levels of metabolic enzymes. The fish antioxidant capacity was significantly enhanced (p < 0.001), and hepatic stress enzymes were greatly (p < 0.001) lowered in FN‐based diets. In summary, the second‐order polynomial regression analysis indicates that the optimal dose of FN supplementation to improve hybrid catfish growth without negatively affecting the fish's physio‐metabolic response or overall wellbeing is 1% dietary inclusion level. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate propofol as an anesthetic and its effects on physiology and histology in Ictalurus punctatus. To determine the ideal concentration, juvenile of I. punctatus (96.60 ± 27.70 g) were used, submitted to different concentrations of the anesthetic: 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, and 6.0 mg L−1. The concentration evaluated as ideal was 2.5 mg L−1. To evaluate the physiological and histological effects of propofol exposure, juvenile of I. punctatus (99.71 ± 26.38 g) were sampled immediately (T0) and 30 min after anesthesia (T30) with 2.5 mg L−1, had blood, liver, and gill samples collected. The exposure of the animals to propofol in both treatments (T0 and T30) caused increases in plasma glucose and lactate levels (p < 0.05) but prevented an increase in cortisol (p > 0.05). The histological study showed mild to moderate changes in the gills (congestion in the lamellar vessels and central vein and epithelial elevation) and moderate and severe changes in the liver (congestion and degeneration). This study concludes that the concentration of 2.5 mg L−1 of propofol provides safe anesthesia for I. punctatus and prevents increased plasma cortisol levels. [ABSTRACT FROM AUTHOR]

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The cyclopoid family Bomolochidae Burmeister, 1835 is one of the most common groups of parasitic copepods infesting fish worldwide. Currently, about 165 species of this family have been reported in marine ecosystems but only a few occur on fish of the family Ariidae Bleeker. During a survey of marine catfish in the Brazilian Amazon Coast, a new species of Boylea Cressey, 1977 was found in the gill chambers of the Thomas sea catfish Notarius grandicassis (Valenciennes) (type-host), Pemecou sea catfish Sciades herzbergii (Bloch) and Coco sea catfish Bagre bagre (Linnaeus) (Siluriformes: Ariidae) off Maranhão Island, State of Maranhão. Boylea inflata sp. nov. can be distinguished from its closest congeners mainly because it has the anterior part of the prosome inflated, the second endopodal segment of leg 3 with one seta and by having a simple outer distal seta on the caudal rami. In addition, an amendment in the diagnosis of Boylea is provided based on the characters present in the new species. Other species of parasitic copepods previously collected from ariid fish off Brazil were revisited and discussed. The present study is the first report of a bomolochid parasitizing the three host species analyzed here, as well as the first report of Boylea in the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

In Egypt, while many studies have focused on the radiometry and mineralogy of black sands, research on their effects on nearby aquatic organisms is rare. This study aimed to assess the combined effects of heat stress (HS) and black sand nanoparticles (BS-NPs) on renal function, antioxidant responses (TAC, SOD, CAT), neuro-stress indicators (AchE, cortisol), and to conduct histopathological investigations in the kidney and spleen tissues of African catfish Clarias gariepinus over a 15-day period to exposure to control, HS (32 °C), BS (6.4 g/kg diet) and HS + BS groups. The outcomes revealed that thermal stress alone showed no significant difference from the control. However, creatinine and uric acid levels were significantly higher in the BS-NPs and HS + BS-NPs groups (p < 0.001). Antioxidant markers (TAC, SOD, and CAT) were substantially reduced across all treated groups (0.05 ≥ p < 0.0001). AchE levels were significantly elevated in BS-NPs and HS + BS-NPs (p < 0.001), while cortisol levels were higher in these groups but not significantly different in HS. Degeneration and necrosis in the white and red pulps, scattered lymphocytes, and increased collagen fiber surrounding blood vessels and the lining of the ellipsoid structure were all evident in the spleen, along with the enlargement of the melanomacrophage centers with big granular, irregular, and brown pigments (hemosiderin). Our study, therefore, provides new insights into how heat stress, an abiotic environmental factor, influences the toxicity of black sand nanoparticles in catfish. [ABSTRACT FROM AUTHOR]

Endocrine cells in the fundic stomach of Clarias gariepinus were characterized in this work using transmission electron microscopy, immunohistochemistry, and histochemistry. Performic acid mixed with alcian blue pH2.5 and silver stain were among the histochemical stains used for endocrine cells. Endocrine cells can be found in the epithelium, lamina propria, submucosa, muscular layer, serosa, and the area between the stomach glands. Endocrine cells with one or more nuclei were found. Endocrine cells were studied using CD3, CD21, and CD68 in an immunohistochemistry analysis. The expression of the lymphocyte marker CD3 by endocrine cells is remarkable. In addition, they had a strong immunological response to CD21 and CD68, which are characteristics of phagocytic cells. Granules of varied sizes and electron densities are packed densely into the cytoplasm of the cells, as seen by transmission electron microscopy. We propose that endocrine cells play a crucial role in immune defense. The role of endocrine cells in the gut's immune system is an area that needs further investigation. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Fisheries Processing Journal / Jurnal Pengolahan Hasil Perikanan Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study investigated the effect of cold preservation on the nutritional composition of two fish species and the role of additives in restoring their quality. Fish samples were stored at 4±1°C for varying durations (0, 24, 48, 72, and 96 hours) and were analyzed. Results showed that proximate composition values progressively decreased with longer storage, while carbohydrate content significantly (P<0.05) increased. Fresh samples had the highest values for all parameters except carbohydrates, which showed the lowest values after 96 hours. Amino acid concentrations (essential and non-essential) did not significantly differ between fresh and stored fish. Leucine was the most abundant amino acid in the Wallago attu, with tryptophan being the least. In Heteropneustes fossilis, leucine and glutamic acid were the highest, while tryptophan and glutamine were the lowest. Mineral content generally declined with storage, except for calcium and zinc in Wallago attu and zinc and iron in Heteropneustes fossilis. Additives helped maintain nutritional value and extended fish shelflife during cold storage. However, significant nutrient loss occurred after an extended storage, which could be mitigated with additives. Cold storage remains a viable method for preserving fish taste and nutrition for a limited time. [ABSTRACT FROM AUTHOR]

Budikdamber innovation represents a technological advancement that combines vegetable cultivation with fish farming in a single system. This initiative is aimed at enhancing food security while providing an alternative source of income for communities. The objective of this study was to assess the sustainability of the catfish budikdamber business. A purposive sampling technique was employed for data collection, and the analysis utilized the sustainable livelihood approach (SLA) with multi-dimensional scaling (MDS). The SLA measured five types of capital: human, natural, financial, physical, and social, using specific indicators. The results indicated that physical capital contributed the most to the sustainability of the business, with a score of 87.49. Conversely, human capital was the lowest, scoring 65.28, signaling a need for improvement in human resource capabilities, particularly in cultivation technology, to ensure long-term sustainability. The overall multimodal average score of 78.41 classified the business as sustainable, with robust support from all five capitals--natural, financial, physical, human, and social. This support helps create economic opportunities for the community, underscoring the potential of the catfish budikdamber business. [ABSTRACT FROM AUTHOR]

Catfish fillets are produced from whole catfish through a series of processing operations including de‐heading, gutting, filleting, skinning, trimming, and freezing. Catfish processing facilities usually chill or freeze a certain number of catfish fillets as backup storage. Later, catfish fillets are pulled out of storage for further processing, where significant manual labor is needed to separate and flatten all the fillets for downstream processing, such as portioning, breading, and individually quick‐frozen (IQF). Due to the labor force shortage and increasing labor cost, there is a pressing need to automate the singulation task, thereby reducing labor dependence. Machine vision technology has been researched for automated quality evaluation of fish products. However, research is lacking on using machine vision for automated singulation of fish fillets. This study presents a novel machine vision system consisting of a color camera for the recognition of the folding status and orientations of catfish fillets toward realizing automated fillet singulation. A set of 400 images of catfish fillets in four different orientations was captured and annotated for each catfish fillet. Two deep learning‐based image segmentation models, that is, YOLOv8 and SegFormer‐B5, were trained on the dataset for catfish fillet recognition. YOLOv8 outperformed SegFormer in catfish recognition and achieved overall masked mAP (mean average precision) scores of 97.1% and 97.4% for underwater and out‐of‐water catfish fillets, respectively. The vision system combined with YOLOv8 has the potential to automate the recognition and subsequent handling operations of catfish fillets. Practical applications: The U.S. catfish industry is shrinking and facing great challenges because of international market competition and increasing production costs. The outbreak of COVID‐19 revealed a sharp deficiency in the labor force for the entire catfish industry, which has relied on manual labor for various processing operations. Mandatory lockdowns severely disrupted seafood supply chains and labor access. The tightening labor market has resulted in the delay of not only catfish processing but also production and distribution. It is imperative to increase the level of automation for processing operations such as IQF preparation process. At present, each processing facility needs 6–10 laborers for the manual catfish fillet IQF preparation process, implying that automating the process would potentially save hundreds of thousands of dollars in annual labor costs per processing line. The automation technology developed in this article has the potential to benefit the U.S. catfish processor by minimizing labor dependence and costs. [ABSTRACT FROM AUTHOR]

Migratory patterns of the catfish Genidens genidens in four estuaries along the Brazilian Atlantic coast are reconstructed from otolith Sr/Ca, a salinity proxy, to test estuarine‐dependency. To facilitate interpretation of this proxy in otolith core‐to‐edge profiles, a Sr/Ca Reference Value for High Salinity (RVHSSr/Ca) of 4.88 mmol/mol was established experimentally, from fish specimens reared in water with a salinity level (33 psu) between estuarine and high salinity (marine) water. All wild specimens exhibited otolith Sr/Ca values higher than RVHSSr/Ca, suggesting that G. genidens utilizes environments with marine salinity. Our results reveal highly variable environmental histories, with at least five major habitat usage patterns. Most distinctive among these, we find that (a) fish from Paranaguá Estuarine Complex (PEC) exhibit high intraindividual heterogeneity; (b) most fish (57%) from Guanabara Bay (GB) exhibit prolonged exposure to very high salinities, often exceeding 36.5 psu levels found in some shelf sectors; and (c) some fish from Paraiba do Sul River, GB and PEC exhibit Sr/Ca values below RVHSSr/Ca consistent with estuarine residence. These results suggest that G. genidens is not strictly estuarine‐dependent. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to analyze the physiological properties, pathogenicity and application of probiotic bacteria to catfish (Clarias sp.) cultivation in vivo. Methodology and results: Probiotic bacteria's physiological characteristics were described using descriptive approaches, whereas experimental methods analyzed pathogenicity tests and the application of the probiotic bacteria in catfish cultivation. The results of bacterial characterization showed that Bacillus safensis strain C251 SA3, Bacillus amyloliquefaciens strain NO10 SA8 and Bacillus australimaris strain IIHR GAPB01 SL1 had bacili cell shape and showed a positive catalase test for all test bacteria except Bacillus safensis strain C251 SA3. The three probiotic bacteria also had negative oxidative-fermentative results, which were able to reduce nitrate and survive in environmental conditions with pH 3-9. Pathogenicity analysis revealed that the three bacteria had the potential to be non-pathogenic or less pathogenic. Bacillus safensis strain C251 SA3 treatment on catfish resulted in the best survival rate of 64% and a 17.5 cm growth in catfish body length by week 13. When Bacillus amyloliquefaciens strain NO10 SA8 was applied to catfish, the survival rate was 32% and the catfish body length increased by 22 cm by week 13. The control treatment revealed that all catfish samples died or had a 0% survival rate, while the application of Bacillus australimaris strain IIHR GAPB01 SL1 revealed a catfish survival rate of 0%. Conclusion, significance and impact of study: Bacillus australimaris strain IIHR GAPB01 SL1 is a potential probiotic bacterium to be applied in catfish food. [ABSTRACT FROM AUTHOR]

This study sought to assess the possibility of genetically improving the performance of the African catfish using triploidy techniques. The experiment was carried out using Completely Randomized Design (CRD) with varied temperatures, time spent before shock after fertilisation, and durations of the shock for the triploid production experiment and four treatments replicated thrice for the culture experiment. Fertilised eggs from each female parent stock were subjected to either cold or heat shock treatments. The result showed a significant (p<0.05) increase in the hatching time and survival of the fertilized eggs subjected to different cold and heat shock treatments as compared to the control which recorded the shortest hatching time of 22.48 ± 0.00 hours. The temperature regime of 2oC recorded the highest approximate yield of triploids (98.33 ± 1.66%), while the prolonged duration of the shock of 30 minutes at the temperature regime of 3oC significantly increased (p<0.05) triploid yield. Comparatively, triploids significantly gained more weight, had an increased growth rate, and grew longer than the diploid counterparts with an average of 11.22 ± 1.07 g, 0.013 ± 0.001%, and 21.49 ± 0.47 cm respectively. The highest comparative cost of the diet of 1000 catfish juveniles occurred in triploids with a stocking density of 7 fishes/m² (N14,132.50). However, the seed, feed, and variable costs consistently decreased with increasing stocking densities across the ploidies. It is therefore concluded that the triploids were superior in both production attributes and cost benefits. [ABSTRACT FROM AUTHOR]

Determining the most appropriate stocking density for a specific fish species in an ambient condition is essential for successful cage aquaculture in terms of profitability which is mainly governed by growth. The current study was conducted to ascertain which stocking density gives the best result of widely cultured species in cage aquaculture, pangas (Pangasianodon hypophthalmus), at swamp forest environment of Ratargul Freshwater Swamp Forest, Bangladesh in terms of growth, production and economic return. Fish were reared for 93 days at three stocking densities, namely 30, 40 and 50 fish/m3 which were denoted as FSD30, FSD40 and FSD50, respectively, containing three replications of each. Growth and yield comparisons indicated that the stocking density of fish had significant (p < 0.05) effects on growth rate and productivity. Fish cultivated at the maximum density (FSD50) had lower mean weights than fish reared at lower densities. The significantly highest mean weights (376.58 ± 14.65 g) and benefit–cost ratio (BCR) (1.617 ± 0.035) obtained from FSD30 show the suitability of this density in terms of fish growth and profitability of pangas in swamp forest environment. [ABSTRACT FROM AUTHOR]

Aquaculture is crucial for global food and nutrition security due to the inability of wild harvests to meet increasing demand. Africa’s contribution to aquaculture is generally low, despite its potential for economic development, food security, and reduced unemployment. The study focuses on the African catfish (Clarias gariepinus) a freshwater fish species that is widely farmed for food in Africa and other parts of the world. Proper nutrition is essential for the growth and development of the fish, and understanding their nutritional requirements is critical for producing healthy and high-quality fish. This review article provides an overview of the knowledge on the nutritional requirement of the African catfish, including protein, lipids, carbohydrates, vitamins, minerals, and amino acids. The recommended protein content for juvenile fish is between 40 and 50% and for adult fish is between 30 and 40%. Based on the reviewed studies, the recommended amount of methionine in C. gariepinus diets ranges from 18.7 to 29.7 g/kg of protein while the lysine requirement ranges from 44.9 to 62.2 g/kg protein). The recommended lipid content in the diet is between 5–15% for juvenile fish and 5–10% for adult fish. The African catfish requires a low-carbohydrate diet, with recommended carbohydrate content between 26 and 32%. They require a variety of vitamins, including vitamin A, vitamin D, vitamin E, and vitamin C, as well as minerals, such as calcium, phosphorus, and potassium. Clarias gariepinus also require a variety of essential and non-essential amino acids. Besides the nutritional requirements, culture conditions also have a significant effect on the feed performance. The recommended conditions include temperature ranging from 28 to 32 °C, Light intensity of 150 Lx, 12D:12L photoperiod, and stocking density in earthen of 7 fish m−3. Overall, understanding the nutritional requirements of C. gariepinus is crucial for the successful fish farming and sustainable aquaculture. Information in this review will be built to further guide the development of feeds for C. gariepinus.

Jatropha curcas is an oil producing seed with high nutritional qualities for consumption. However, due to inherent anti-nutritional factors, appropriate processing is necessary to improve its nutrients utilization. This study was aimed at processing J. curcas using solvent-extraction method and evaluating its inclusion effects in the diet for Clarias gariepinus on its growth status. J. curcas meal was extracted using 80 % methanol to remove phorbol esters and other anti-nutrients. Thereafter, five iso-nitrogenous diets (40 % crude protein) were formulated containing J. curcas meal replacements of soybeans meal at 0 % (TRT0), 25 % (TRT25), 50 % (TRT50), 75 % (TRT75) and 100 % (TRT100) and fed to C. gariepinus for 70 days. Results showed that TRT25 fish had the highest mean weight gain and specific growth. The serum alkaline phosphate, alanine aminotransferase, and aspartate aminotransferase levels began to rise significantly (p ≤ 0.05) at 50 % replacement. Likewise, the assessment of gut ecology and morphology indicated that TRT25 had significantly (p ≤ 0.05) the highest gut bacteria colony forming unit (2.60 ×104±0.02cfu/g) and most favorable area of absorption (0.16±0.01 cm2). The histopathological observation of the fish intestine, liver and gills indicated no visible deformity in TRT0 and TRT25 fish. However, various degrees of degenerations were observed in the fish fed with 50 % and higher inclusion of J. curcas. This study showed that methanol-extracted J. curcas meal can be effectively utilized for C. gariepinus at 25 % of replacement.

IntroductionGeometric aquaculture growth has resulted in exponentially increasing use of agrochemicals as either parasiticides or herbicides in the aquaculture environment. This study determines some of the toxicological (haematological and biochemical) effects of glyphosate-based herbicides on non-target aquatic animals using Clarias gariepinus as the animal model.MethodSeventy-five apparently healthy adult C. gariepinus (300 g) were sourced from a local farmer and acclimatised for 2 weeks; of these, sixty subjects were divided into four treatment groups (fifteen fish per group and five replicates per unit) by simple randomisation and labelled as T0 (control), T1 (first treatment), T2 (second treatment), and T3 (third treatment). The treatments were replicated thrice. Four concentrations of Force up® [0 mL, 0.15 mL (0.003 mL/L or 5.1 mg/L), 0.225 mL (0.0045 mL/L or 7.65 mg/L), and 0.3 mL (0.006 mL/L or 10.2 mg/L) were added to a 50-L tank of water for T0, T1, T2, and T3, respectively. Approximately 5 mL of blood was collected from the fish in each treatment group 96 h post-exposure for measurement of the blood parameters and biochemical indices using standard analytical methods as well as calculation of the mean values.ResultThe mean values of the packed cell volume, haemoglobin concentration, red blood cell count, and white blood cell count compared to the control group showed an initial increase at T1 but decreased as the glyphosate concentrations increased at T2 (0.0045 mL/L) and T3 (0.006 mL/L). The platelet mean values decreased at T1, increased at T2, and decreased at T3, while the mean values of the corpuscular volume, corpuscular haemoglobin, and corpuscular haemoglobin concentration increased with glyphosate concentration, with the mean corpuscular haemoglobin concentration decreasing at T2. Only the platelet value was statistically significant at a p-value of 0.05.DiscussionBased on the results of this study, it is deduced that glyphosate-based herbicide (Force up®) has genotoxic, hepatotoxic, and nephrotoxic effects on C. gariepinus even at sublethal doses, with more adverse effects at increasing concentrations.

Abstract Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host’s adaptive responses.

Application of commercial hormone failed to promote breeding in certain Pangasius species due to the differences of gonadotropin- releasing hormone specific peptide with species-specific bioactivities. Gonadotropin-releasing hormone (GnRH) is a hypothalamic decapeptide in the reproductive system that plays a crucial role in the regulation of reproductive processes. This study was performed to determine and analyse the GnRH genes from commercially important Pangasius sp., Pangasianodon hypophthalmus and Pangasius nasutus. The GnRH1 and GnRH2 genes were amplified and cloned into TOPO vector, followed by phylogenetic analysis of a complete open reading frame (ORF) of GnRH genes. The GnRH1 and GnRH2 genes of P. hypophthalmus and P. nasutus were detected at 300 bp and 360 bp, encoded for 81 and 87 amino acids, respectively. Amino acid sequence identities revealed high homology of P. hypophthalmus and P. nasutus GnRH1 and GnRH2 genes in comparison with other fish and vertebrates. Phylogenetic tree showed that fish from various families were aggregated into a group of the same order due to their highest identity similarities. It revealed that the vertebrate formed clusters and are grouped according to their GnRH decapeptide and GnRH-associated peptide (GAP) region, indicating a close relationship among GnRH decapeptide and GAP in different vertebrate species.

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host's adaptive responses. [ABSTRACT FROM AUTHOR]

This study aims to analyze the administration of microencapsulated probiotic Bacillus cereus BR2 through feed atdifferent doses on the survival, immune response, and digestive enzyme activity of catfish Clarias sp. infected with Aeromonas hydrophila NFC1. The research design consisted of five treatments and three replications, (K-) feeding without the supplementation of probiotics fish injected with Phosphate-buffered saline solution, (K+) feeding without the supplementation of probiotics fish injected with A. hydrophila NFC1 cell suspension (106 CFU/mL), (P1) feeding with supplementation of B. cereus BR2 microcapsules at a dose of 0.5% (w/w), (P2) feeding with the supplementation of B. cereus BR2 microcapsules at a dose of 1% (w/w; (P3) feeding with the supplementation of B. cereus BR2 microcapsules at a dose of 2% (w/w). All treatments of P1, P2, and P3 were intramuscularly injected with A. hydrophila NFC1 cell suspension. Catfish in average body weight of 3.73 ± 0.22 g were reared in tanks filled with 30 liters of water, at a density of 15 fish per container. A feed supplementation trial was performed for 40 days with feeding times three times a day and a 5% feeding rate reevaluated based on biomass. Fish rearing was continued after the challenge test with A. hydrophila NFC1 for 10 days. The results showed that the application of supplemented feed containing B. cereus BR2 probiotic microcapsules increased the survival rate, immune response, and digestive enzyme activities of catfish which was infected with A. hydrophila NFC1, 2% microcapsule supplementation demonstrated the best result. [ABSTRACT FROM AUTHOR]

In a recent study based on the generalized mixed Yule coalescent method for delimiting species, a threshold of 2% genetic distance using cytochrome c oxidase subunit I sequences was used to delimit the species of Microglanis. That action resulted in assembling several populations of Microglanis from Atlantic coastal rivers between Rio Grande do Sul and São Paulo states as a single species, Microglanis cottoides, including Microglanis cibelae as a junior synonym. We reexamined these populations and found three species diagnosed by their morphology and that constitute separate mtDNA lineages, including a new species. The synonym of M. cibelae and M. cottoides is reviewed and refuted based on morphological and molecular evidence. M. cibelae and the new species are sympatric and occasionally syntopic in the Tramandaí, Mampituba, and Araranguá river basins. The new species is distinguished from M. cibelae and M. cottoides by the anterior margin of the posttemporosupracleitrum narrow articulated with the epioccipital, the short mental and maxillary barbels, and depressed head and body. [ABSTRACT FROM AUTHOR]

Importance: Over the past decade, catfish farming has increased in Southeast Asia. However, there has been no existing for pharmacokinetic data in the hybrid catfish ( Clarias macrocephalus x C. gariepinus). Objective: This study was designed to evaluate the pharmacokinetic characteristics of oxytetracycline (OTC) in the hybrid catfish, following single intravascular (IV) or oral (PO) administration at a single dosage of 50 mg/kg body weight (BW). Methods: In total, 140 catfish (each about 100-120 g BW) were divided into two groups (n = 70). Blood samples (0.6-0.8 mL) were collected from ventral caudal vein at pre-assigned times up to 144 h (sparse samples design). OTC plasma concentrations were analyzed using high-performance liquid chromatography-photodiode array detector. Results: The pharmacokinetic parameter of OTC was evaluated using a non-compartment model. OTC plasma concentrations were detectable for up to 144 and 120 h after IV and PO, respectively. The elimination half-life value of OTC was long with slow clearance after IV administration in hybrid catfish. The average maximum concentration value of OTC was 2.72 µg/mL with a time at the maximum concentration of 8 h. The absolute PO bioavailability was low (2.47%). Conclusions and Relevance: These results showed that PO administration of OTC at a dosage of 50 mg/kg BW was unlikely to be effective for clinical use in catfish. The pharmacodynamic properties and clinical efficacy of OTC after multiple medicated feed are warranted. [ABSTRACT FROM AUTHOR]

Copyright of JFMR - Journal of Fisheries & Marine Research is the property of Brawijaya University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to isolate and identify pathogenic bacteria in the intestinal tract, skin, and muscles of Sciades herzbergii; detect histopathological changes in the gill and liver; and use these biomarkers for the assessment of potential risks to human health. Fish were sampled during the rainy and dry seasons at two points in São Marcos Bay, Maranhão, Brazil: Ilha dos Caranguejos (IC) and Porto Grande (PG). Isolation and quantification were carried out using COLItest®. Colonies were subjected to identification and phenotypic investigation of antimicrobial resistance using Vitek®. Gill and liver samples were subjected to routine histological examination. The results indicated the presence of Klebsiella pneumoniae and Escherichia coli, the latter of which showed phenotypic resistance to norfloxacin and gentamicin. Fish caught at PG exhibited more extensive gill and liver damage than fish caught at IC. The findings suggest that histological changes in target organs of S. herzbergii may be influenced by infection with pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to quantify the economic costs and impacts of off‐flavor on U.S. catfish farms. Methods: A survey was conducted to quantify the costs and economic methods using enterprise budget techniques to enumerate the costs of off‐flavor on catfish farms. Result: Diuron was the most popular‐choice algicide for off‐flavor management. Direct annual costs associated with off‐flavor management on catfish farms amounted to US$40 million/year. Total industry economic losses due to off‐flavor was estimated at $73.9 million in 2022. Conclusion: The study confirms the continued significance of off‐flavor in U.S. catfish farming and quantifies the associated economic effects. Impact statementEvaluating the economic cost associated with off‐flavor management practices provides insights into the economic significance of this persistent problem on U.S. catfish farms. This study found that the annual cost of off‐flavor amounts to $2325/ha and $0.272/kg, accounting for 10% of the total cost of production. The direct economic loss to the industry amounted to $40 million annually, with a total negative economic impact of $74 million in 2022. [ABSTRACT FROM AUTHOR]